why is that when creating deliveries sometimes pick quantities can be updated and packing can be done and PGI done in that order whereas in some case pick quantity cannot be updated and hence PGI cannot be done without Transfer Order..?
Some materials are not pickable in the sense that they are managed by WMS. So instead of doing picking and packing , for materials managed by WMS , a transfer order is done and PGI done.
To make an item category relevant for picking goto IMG->LE->Shipping->Picking->Define Relevant Item Categories.